One widespread procedure for cleaning floors commercially requires that the floor be pre-swept or vacuumed, normally by hand, prior to using a floor scrubbing or carpet extraction machine to clean the surface. Automatic floor scrubbers and carpet extraction machines typically use a water spray or gravity feed from a solution tank applied directly to the floor (after the loose dirt and debris are removed manually or by a separate vacuum machine), followed by a series of brushes which may include cylindrical scrub brushes, a group of disc scrub brushes or a combination of the two, to work the solution into the floor and loosen dirt and debris.
Following the brushes, a squeegee or vacuum suction device recovers the spent solution from the floor, and returns it to a separate tank which is commonly referred to as the recovery tank. Automatic scrubbing machines of this type, if used in an area in which there is a lot of loose dirt and debris, as indicated, generally require separate vacuuming, sweeping or dusting of the area before scrubbing. If the area is of substantial size, these two operations, pre-removal of loose material followed by machine scrubbing, may consume considerable time and require the use of a separate pre-removal machine and then application of a scrubbing machine. Moreover, automatic floor scrubbers are expensive, particularly more current machines such as rider/scrubbers.
At least one rider/scrubber does have a dual sweeping/scrubbing capacity, with a forward-sweeping cylindrical brush for sweeping loose debris into a forward hopper, followed by a rear scrub deck with two or more disc scrub brushes. A rear squeegee recovers the dirty solution, which is stored in a recovery tank and must be discharged into a drain. Such machines use a considerable amount of solution and may leave a substantial amount of water behind the scrub deck. The spent solution is recovered and stored on the machine, to be discarded after a cleaning run.
For scrubbing machines designed for application to larger areas, the size of the machine may be limited by design constraints such as maneuverability and the need to provide operator visibility of the floor area in front of the machine. Currently, in the case of battery-operated scrubbing machines, the physical size of a typical battery pack may occupy a substantial portion of the overall machine. Another factor in determining the size of the machine is the volume of cleaning solution that the machine is capable of storing and which is recovered and stored until discarded. As mentioned, the cleaning solution, after application to the floor and operation of the scrub brushes, is typically recovered by suction and stored in the same machine until discarded. The machine must be moved or driven to an area where the dirty water may be discharged. The presence of two separate tanks, one for clean solution and one for spent solution acts as a limitation on the total area the machine may treat before the need to replace the clean solution and discharge the dirty solution. However, the size of the tanks are restrained because of the overall size limitations on the machine for practical reasons, and the presence of bulky batteries.
Various arrangements, including the use of a movable wall in a combination cleaning solution/recovery solution double-tank system, have been employed to overcome the space limitation problem of storing sufficient volumes of solution and recovered water. Nevertheless, the size of the typical commercial scrubbing machine has limited the area which the machine may clean before returning to the supply closet to discharge the spent solution and to place additional clean solution in the clean solution tank. Thus, the size of the solution tanks as well as the volume assumed by the batteries act to limit the application area of a conventional cleaning machine, even if the cost of the machine were not a factor.